Method of making a micro-fluid ejection device

ABSTRACT

A method is provided for making a multi-fluid cartridge for holding multiple fluids in segregated containment localities. The cartridge body contains fluid supply paths in fluid flow communication with the containment localities. A nozzle plate is attached to a device side of each of a plurality of defined ejection head substrates on a semiconductor wafer. Each of the ejection head substrates has a fluid supply side and two or more fluid flow paths therein for supplying fluid from the supply side to the device side thereof. The fluid flow paths in the ejection head substrates have a flow path density of greater than about 1.0 flow paths per millimeter. The wafer is diced to provide a plurality of micro-fluid ejection device structures. A circuit device is attached to the device side of each of the substrates. An adhesive is stencil printed with a bond line density of at least about 1.2 mm −1  on the micro-fluid ejection device structures or on the cartridge body. At least one of the micro-fluid ejection device structures and attached circuit is adhesively bonded to the cartridge body for flow of fluid from the containment localities to the device side thereof.

This application is a continuation of prior application Ser. No.10/880,899, filed on Jun. 30, 2004 now U.S. Pat. No. 7,043,838, theentire disclosure of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The disclosure relates to micro-fluid ejection devices and in particularto structures and techniques for securing a semiconductor substrate to amulti-fluid reservoir.

BACKGROUND OF THE INVENTION

In the field of micro-fluid ejection devices, ink jet printers are anexemplary application where miniaturization continues to be pursued.However, as micro-fluid ejection devices get smaller, there is anincreasing need for unique designs and improved production techniques toachieve the miniaturization goals. For example, the increasing demand ofputting more colors in a single inkjet cartridge requires the additionof fluid flow passageways from the cartridge body to the ejection headthat, without radical changes in production techniques, will requirelarger ejection head substrates. However, the trend is to furtherminiaturize the ejection devices and thus provide smaller ejection headsubstrates. An advantage of smaller ejection head substrates is areduction in material cost for the ejection heads. However, this trendleads to challenges relating to attaching such substrates to amulti-fluid supply reservoir.

As the ejection heads are reduced in size, it becomes increasinglydifficult to adequately segregate multiple fluids in the cartridges fromone another yet provide the fluids to different areas of the ejectionheads. One of the limits on spacing of fluid passageways in the ejectionhead substrate is an ability to provide correspondingly small, andclosely-spaced passageways from the fluid reservoir to the ejection headsubstrate. Another limit on fluid passageway spacing is the ability toadequately align the passageways in the fluid reservoir with thepassageways in the ejection head substrate so that the passageways arenot partially or fully blocked by an adhesive used to attach to theejection head to the reservoir.

Thus, there continues to be a need for improved structures andmanufacturing techniques for micro-fluid ejection head components forejecting multiple fluids onto a medium.

SUMMARY OF THE INVENTION

With regard to the foregoing, the disclosure provides a micro-fluidejection device structure, a multi-fluid cartridge containing theejection device structure, and methods for making the ejection devicestructure and cartridge. In one embodiment, a method is provided formaking a multi-fluid cartridge for holding multiple fluids in segregatedcontainment localities. The cartridge body contains fluid supply pathsin fluid flow communication with the containment localities. A nozzleplate is attached to a device side of each of a plurality of definedejection head substrates on a semiconductor wafer. Each of the ejectionhead substrates has a fluid supply side and two or more fluid flow pathstherein for supplying fluid from the supply side to the device sidethereof. The fluid flow paths in the ejection head substrates have aflow path density of greater than about 1.0 flow paths per millimeter.The wafer is diced to provide a plurality of micro-fluid ejection devicestructures. A circuit device is attached to the device side of each ofthe substrates. An adhesive is stencil printed with a bond line densityof at least about 1.2 mm⁻¹ on the micro-fluid ejection device structuresor on the cartridge body. At least one of the micro-fluid ejectiondevice structures and attached circuit is adhesively bonded to thecartridge body for flow of fluid from the containment localities to thedevice side thereof.

One advantage of the apparatus and methods disclosed herein could bethat multiple different fluids can be ejected from a micro-fluidejection device that is less costly to manufacture and has dimensionsthat enable increased miniaturization of operative parts of the device.Continued miniaturization of the operative parts enables micro-fluidejection devices to be used in a wider variety of applications. Suchminiaturization also enables the production of ejection devices, such asprinters, having smaller footprints without sacrificing print quality orprint speed. The apparatus and methods described might reduce the sizeof a silicon substrate used in such micro-fluid ejection devices withoutsacrificing the ability to suitably eject multiple different fluids fromthe ejection device.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the embodiments described herein will becomeapparent by reference to the detailed description of exemplaryembodiments when considered in conjunction with the drawings, whereinlike reference characters designate like or similar elements throughoutthe several drawings as follows:

FIG. 1 is a top perspective view of an inside cavity of a multi-fluidcartridge body according to the disclosure;

FIG. 2 is a perspective view of a micro-fluid ejection device;

FIG. 3 is a top plan view of a multi-fluid cartridge body according tothe disclosure;

FIG. 4 is a side cross-sectional view of a multi-fluid cartridge bodyaccording to the disclosure;

FIG. 5 is a perspective exploded view of a multi-fluid cartridge bodyaccording to the disclosure;

FIG. 6 is a cross-sectional view, not to scale of a micro-fluid ejectionstructure attached to a multi-fluid cartridge body;

FIG. 7 is an exploded perspective view, not to scale, of a multi-fluidcartridge body made according to another embodiment of the disclosure;

FIG. 8 is a cross-sectional view not to scale of a portion of amicro-fluid ejection head structure attached;

FIG. 9 is a schematic view of an adhesive application process for amicro-fluid ejection device structure according to the disclosure;

FIG. 10 is a cross-sectional view, not to scale, of a stencil or screenprinted adhesive on a micro-fluid ejection device structure according tothe disclosure;

FIG. 11 is a perspective view not to scale of a semiconductor wafer witha plurality of ejection head substrates;

FIG. 12 is a cross-sectional view, not to scale of a portion of asemiconductor wafer with an ejection head substrate;

FIG. 13 is a perspective view, not to scale, of a photoresist laminatematerial for applying to a semiconductor wafer according to thedisclosure;

FIG. 14 is a cross-sectional view, not to scale, of a semiconductorwafer with a photoresist material layer;

FIG. 15 is a schematic illustration of a patterning process for aphotoresist material layer on a semiconductor wafer according to thedisclosure;

FIG. 16 is a schematic illustration of a developing process for aphotoresist material layer on a semiconductor wafer according to thedisclosure;

FIGS. 17-18 are cross-sectional views, not to scale, of ejection headstructures attached to multi-fluid cartridge bodies according toembodiments of the disclosure;

FIG. 19 is a plan view, not to scale, of an ejection head substrateaccording to one embodiment of the disclosure;

FIGS. 20-22 are plan views, not to scale, of photoresist material layershaving flow channel portions patterned and developed therein accordingto an embodiment of the disclosure; and

FIG. 23 is an exploded view, not to scale, of an ejection head substrateand two photoresist material layers according to an embodiment of thedisclosure.

DETAILED DESCRIPTION

With reference to FIGS. 1-5, a multi-fluid cartridge body 10 for amicro-fluid ejection device, such as an ink jet printer 12 isillustrated. The multi-fluid body 10 includes a body structure 14 havingexterior side walls 16, 18, 20, and 22 and a bottom wall 24 forming anopen-topped, interior cavity 26. An ejection head area 28 is disposedadjacent a portion 30 of the bottom wall 24 opposite the interior cavity26. At least two segregated fluid chambers 32 and 34 are provided withinthe interior cavity 26 of the body 10. A dividing wall 36 separateschamber 32 from chamber 34. An additional dividing wall 38 may beprovided to separate chamber 40 from chamber 32 for a body 10 containingthree different fluids. Independent fluid supply paths are provided fromeach of the fluid chambers 32, 34, and 40 to provide fluid to anejection head structure 44 attached adjacent the ejection head area 28of the body 10. The fluids are retained in the chambers 32, 34, and 40by a cover 42 attached to the fluid body 10.

The body structure 14 is preferably molded as a unitary piece in athermoplastic molding process. A preferred material for the bodystructure 14 is a polymeric material selected from the group consistingof glass-filled polybutylene terephthalate available from G.E. Plasticsof Huntersville, N.C. under the trade name VALOX 855, amorphousthermoplastic polyetherimide available from G.E. Plastics under thetrade name ULTEM 1010, glass-filled thermoplastic polyethyleneterephthalate resin available from E. I. du Pont de Nemours and Companyof Wilmington, Del. under the trade name RYNITE, syndiotacticpolystyrene containing glass fiber available from Dow Chemical Companyof Midland, Mich. under the trade name QUESTRA, polyphenyleneether/polystyrene alloy resin available from G.E. Plastics under thetrade names NORYL SEI and NORYL 300X and polyamide/poly-phenylene etheralloy resin available from G.E. Plastics under the trade name NORYL GTX.A preferred material for making the body structure 14 is NORYL SEIresin.

Ejection head structure 44 contains fluid ejection actuators such asheater resistors or piezoelectric devices to eject fluid from theejection head structure 44. Fluid to the actuators is provided from thebody 10 to corresponding fluid flow paths 46-50 in the ejection headstructure 44. A flexible circuit 52 containing electrical contacts 54thereon is provided and attached to the ejection head structure 44 andbody 10 to provide electrical energy to the actuators when the body 10is attached to an ejection device such as ink jet printer 12.

Providing two or more chambers 32, 34, and 40 in a single body 10increases the technical difficulties of using an injection moldingprocess for making the body 10. If the body 10 is to be molded from apolymeric material as a single molded unit, there are significantchallenges to molding suitable fluid supply paths in the body 10 to theejection head area 28 using conventional mold construction and moldingtechniques. Such challenges include, but are not limited to, thecomplexity of cooling and filling the mold used for the injectionmolding process.

A multi-fluid body, such as body 10, also presents challenges forsealing the ejection head structure 44 to the ejection head area 28without blocking narrow fluid passageways in the ejection head area 28of the body 10. For example, as shown in FIG. 6, an ejection headstructure 44 having fluid flow paths 46, 48, and 50 therein is attachedas by a die bond adhesive 56 to a multi-fluid body 58 having fluidsupply paths 60, 62, and 64 therein. For a narrow ejection headstructure 44 having a high density of fluid flow paths 46-50, it isdifficult to adhere such head structure 44 directly to the body 58 usingconventional adhesive techniques. In this case, fluid flow paths 46 and50 are blocked or are partially blocked by the adhesive 56.

For purposes of this disclosure, the number of fluid supply paths withina given linear dimension W is defined as the flow path density. The term“high density” means that for a given dimension W of the ejection headstructure 44, there are more than one fluid flow paths 46-50 permillimeter.

Yet another multi-fluid body 70 is illustrated in FIG. 7. In FIG. 7,instead of a single multi-compartmentalized body 10 as illustrated inFIGS. 1 and 3-5, individual fluid containers such as fluid containers 72and 74 are provided. The fluid containers 72 and 74 have fluid cavities76 and 78 therein for different fluids. The fluid cavities 76 and 78 areclosed by covers 80 and 82. A fluid outlet port 84, 86 is provided foreach container 72, 74. The containers 72, 74 are inserted into acontainer housing 88 that contains a standpipe assembly 90 for fluidlycoupling the outlet ports 84, 86 of the containers 72, 74 to an ejectionhead structure such as ejection head structure 44. The outlet ports 84,86 of the containers 72, 74 are fluidly coupled to the standpipeassembly 90 when the containers 72, 74 are disposed in the containerhousing 88.

A portion 100 of a typical micro-fluid ejection device structure 44 isillustrated in FIG. 8. The portion 100 illustrated in FIG. 8 contains athermal fluid ejection device 102. The portion 100 also includes asemiconductor substrate 104 containing multiple conductive, insulative,and protective layers 106 for forming and protecting the fluid ejectiondevice 102. A nozzle plate 108 containing nozzle holes 110 is attachedto the substrate 104 and layers 106 to provide a fluid ejection chamber112. Fluid flows to the fluid ejection chamber 112 from the cartridgebody 10, or containers 72, 74 through a fluid supply channel 114 that isin flow communication with the fluid flow paths 46-50 in the micro-fluidejection device structure 44. While a thermal fluid ejection device 102is illustrated in FIG. 8, the disclosure is also applicable to othertypes of fluid ejection devices including, but not limited to,piezoelectric fluid ejection devices.

It will be appreciated that as the number of fluid cavities forproviding different fluids to the ejection device structure 44increases, it becomes increasingly difficult to align and attach theejection device structure 44 to the ejection head area 28 of the body10. As described in more detail below, there are several uniquesolutions to the problem associated with increasing the number of fluidflow paths 46-50 per width W of the ejection device structure 44. Thebelow described solutions also enable narrower, and thus smallerejection device structures 44 to be used for multi-fluid bodies thanwould otherwise be suitable for such applications.

In one embodiment there is provided a method of dispensing an adhesivefor bonding a micro-fluid ejection device structure to a multi-fluidbody. Typically, the adhesive 56 is dispensed with a needle to a bondingarea 120 of the body 58 (FIG. 6). Adhesive 56 dispensed in this mannerhas a bond line width AW of about 500 microns and a bond line height AHof about 100 microns. While the ejection head structure 44 typically hasa substantially planar surface 122 for bonding to the body 58, the body58 may not have such the substantially planar surface area 120 forbonding.

For suitably sealing between fluid flow paths 46-50, the planarity ofthe bonding surface 120 of the body 58 is preferably controlled withinplus or minus 50 microns. However, for smaller bond line widths AW,smaller bond line heights AH are required. For a bond line width of 200microns, the desired bond line height AH is about 25 microns.Accordingly, the planarity of the bonding surface 120 of the body 58should be controlled within plus or minus 10 microns to get a good sealbetween flow paths 46-50 during a step used to bond the structure 44 tothe body 58.

An improved method of bonding, according to one embodiment of thedisclosure, includes a stencil or screen printing method for applyingthe adhesive to the ejection head structure 44 or body 10. According tothe method, as illustrated schematically in FIG. 9, a stencil or screen124 having precisely placed openings is used to apply an adhesive 126 onthe ejection head structure 44 or on the body 10 in the ejection headarea 28. Such a process will enable bond line widths AW down to about 10microns and bond line heights AH down to or below about 10 microns. Apreferred bond line width AW′ ranges from about 10 to about 500 microns,preferably from about 200 to about 400 microns. Such bond linedimensions for the adhesive 126 enable an ejection head structure widthW reduction directly proportional to a total area required for theadhesive bond lines.

Another advantage of stencil and/or screen printing the adhesive 126 onthe ejection head structure 44 could be that over compression of theadhesive 126 in the bonding area between the head structure 44 and thebody 10 is minimized. Adhesive over compression can lead to adhesivebulging into the fluid flow paths 50 and 46 as illustrated in FIG. 6.Accordingly, an adhesive applied to the ejection head structure 44 orbody 58 using a conventional needle dispensing technique and having anadhesive bond line width AW of 550 microns may be over compressed duringbonding resulting in an adhesive bulge with an overall width of 650microns. Such a bulge in the adhesive 56 may cause flow restriction orblockage as shown in FIG. 6. The more precise stencil and screenprinting method of applying the adhesive 126 provides improved controlover adhesive bond line height AH′ and thus over adhesive overcompression during bonding.

Tighter control over the bond line height and bond line width enables agreater density of adhesive bond lines to be applied to the headstructure 44 or body 10. A greater density of adhesive bond lines canprovide either more bond lines for a given bonding area or can providethe ability to bond a smaller ejection head structure 44 to the body 10.In this case, the bond line width AW′ is equivalent to the amount ofadhesive required to seal between adjacent flow paths 46-50.

For an ejection head structure 44 having 3 parallel flow paths 46-50,four bond lines 128 (FIG. 10) seal the ejection head structure 44 to thebody 10. An ejection head structure containing n number of parallel flowpaths 46-50 will typically utilize n+1 of the bond lines 128 to seal theflow paths to the body 10. An exception to this is when a fluid chamberin a body provides the same fluid to two or more of the flow paths inthe ejection head structure. Accordingly, the foregoing method enables asubstantial increase in bond line density. For the purposes of thisdisclosure, the bond line density is defined as the number of the bondlines 128 between parallel flow paths 46-50 divided by a linear distanceLD between the flow paths 46-50 as shown in FIG. 10. Conventionaltechnology enables a bond line density of about 0.7 mm⁻¹. The foregoingstencil and/or screen printing method enables bond line densities ofgreater than about 0.7 mm⁻¹, preferably from about 0.8 to about 2 mm⁻¹.

Materials that may be used as die bond materials or adhesives 126 forsuch applications include, but are not limited to, 3193-17 from Emersonand Cumings, M308.1 from EMS and 504-48 from EMS. These materials arealso chemically compatible with the body material (NORYL SEI) describeabove. When the die bond area becomes smaller and smaller, precisionalignment of the paths and/or channels is crucial.

An increase in flexibility of design for smaller ejection head structure45 may also be provided by use of one or more of the followingembodiments incorporating a photoresist manifold structure. According toone such embodiment, a photoresist material, either a positive ornegative photoresist material, is applied to a semiconductor wafer 150having a plurality of semiconductor substrates 152 defined thereon asshown in FIG. 11. Each of the substrates 152 contains ejection devicesas described above on a device side thereof. The substrates 152 alsocontain flow paths formed therein, such as flow paths 154-158 (FIG. 12).According to the process, a photoresist material is applied to a fluidsupply side 160 of the wafer 150. The photoresist material may be spinor spray-coated onto the wafer 150 or applied as a film or web 162 (FIG.13) to the wafer 150.

Commercially available dry film photoresist materials include acrylicbased materials, such as a material available from Mitsui of Japan underthe trade name Ordyl PR132, epoxy based materials, such as a materialavailable from E. I. DuPont de Nemours and Company Corporation ofWilmington, Del. under the trade name RISTON, or a material availablefrom MicroChem Corporation of Newton, Mass. under the trade name SU-8(or such as a proprietary material internally used at LexmarkInternational, Inc. of Lexington, Ky. and referred to internally asGSP920), and polyimide-based photoresist materials, such as a materialavailable from HD Microsystems of Parlin, N.J. under the trade nameHD4000.

After applying the photoresist material 162 to the fluid supply side 160of the wafer 150 (FIG. 14), the photoresist material 162 is exposed, asthrough a mask 164 to actinic radiation 168, such as ultraviolet (UV)light (FIG. 15) to pattern the photoresist material 162 to providelocations 166 for fluid flow channels in the photoresist material 162upon developing the photoresist material 162. The patterned photoresistmaterial 162 is then developed by dissolving uncured material from thefluid supply side 160 of the wafer 150 as shown in FIG. 16 using adeveloping chemical 170. The developing chemicals 170 may be selectedfrom tetramethyl ammonium hydroxide, xylene or aliphatic hydrocarbons,sodium carbonate, and 2-butyl cellosolve acetate (BCA).

In an exemplary embodiment, the dry film photoresist material 162 islaminated to the wafer 150 at a temperature of about 50° C. and apressure of 60 pounds per square inch gauge. The photoresist material162 is exposed to UV radiation through the mask 164 for about fourseconds at an energy of 18.6 milliwatts. After patterning thephotoresist material, a development step is performed in which BCA ispuddled onto the exposed photoresist material from about 1 minute. Next,BCA is sprayed onto the photoresist material for about 30 seconds. Thewafer 150 is spin-dried for about 30 seconds. Then the photoresistmaterial 162 is cured at about 180° C. for about two hours. The curedphotoresist material 162 has the fluid flow channels 166 therein influid flow communication with the fluid flow paths 154-158 in thesubstrate 152.

After curing the photoresist material 162, a nozzle plate is attached toeach of the substrates 152 to provide the ejection head structure 44described above with reference to FIG. 6. The wafer 150 is then diced toprovide individual ejection head structures 44 and flexible circuits,such as circuits 52, are electrically connected to the ejection headstructures 44. Depending on the adhesive characteristics of thephotoresist material 162, the ejection head structures 44 may becompression bonded to the body 10 or an adhesive may be applied to thephotoresist material 162 on the ejection head structure or to the body10 using the stencil or screen printing method described above. Anillustration of an ejection head structure 44 attached to a body 172 asdescribed above is illustrated in FIG. 17.

In another embodiment, illustrated in FIG. 18, the manifold is providedby a multi-layer photoresist material 180. The multi-layer photoresistmaterial 180 provides a greater degree of freedom in ejection headstructure 44 design and body 172 design. FIGS. 19-23 illustrate onemulti-layer photoresist material design which can enhance the adhesionof the head structure 44 to the body 172 without substantially blockingfluid flow paths 46-50 in the head structure 44.

FIG. 19 is a plan view of a fluid supply side of a head substrate 152having fluid supply paths 154-158. A first layer of photoresist material182 contains fluid flow channels portions 184, 186 and 188 which have alarger open area than the fluid flow paths 154-158. Accordingly, each ofthe fluid flow channels portions 184, 186, and 188 have a widthdimension 190 that is from about 1 to about 200% wider than the fluidflow path width 192 of the ejection head structure 44. The widthdimension 190 improves fluidic flow to the fluid flow paths 154-158while providing sufficient area for reliably sealing between the fluidflow paths 154-158.

In a next photoresist layer 194, fluid flow channel portions 196, 198,and 200 have flow areas substantially the same as the flow areas ofchannel portions 184, 186, and 188, however the flow channel portions196, 198, and 200 are substantially shorter than the flow channelportions 184, 186 and 188. The shorter flow channel portions 196, 198,and 200 provide increased surface area adjacent the flow channelportions 196, 198 and 200 for sealing fluid supply paths 202 in the body172 (FIG. 18). However, the flow channel portions 196, 198, and 200 aresufficient to direct the fluid to the intended fluid flow paths 154-158.Additional photoresist layers can be provided, such as layer 204containing fluid flow channel portions 206, 208, and 210 therein forflow communication with fluid flow paths 154-158. For illustrativepurposes only, FIG. 23 illustrates an overlay of the photoresist layer194 on the photoresist layer 182 which is laminated to the ejection headsubstrate 152.

Each of the photoresist layers 182, 194, and 204 would be applied, as bya photoresist laminate, spin coating, spraying, or screening to thefluid supply side 160 of the wafer 150. The photoresist layers 182, 194,and 204 may be applied before or after forming the fluid flow paths46-50 in the substrate 152. After applying the photoresist layers 182,194, and 204 to the wafer 150, each of the photoresist layers 182, 194,and 204 may be patterned and developed as describe above with referenceto FIGS. 11-16.

Certain photoresist layers 182, 194, and 204 may be selected frommaterials that enable direct attachment of the ejection head structure44 to the body 172 using, for example, a thermal compression bondingprocess wherein heat and pressure are applied to the ejection headstructure 44. Heat may be used to initially laminate a photoresist layeror layers to the wafer 150. A secondary heating process may then be usedto adhere the photoresist layer or layers to the body 172. For example,a negative photoresist material may be laminated or applied to the fluidsupply side 160 of the wafer 150 using a dry film photoresist containingthermoplastic component such as the material described in U.S. Pat. No.5,907,333 or a B-staged photoresist such as HD4000 polyimidephotoimagable resist. After the photoresist layer is developed, asecondary heating process may allow the photoresist layer to be adhereddirectly to the body 172.

An alternate process may include a negative photoresist material that islaminated or applied to the fluid supply side 160 of the wafer 150 priorto forming the fluid flow paths 154-158 in the substrates 152. Thenegative photoresist material could be patterned but not developed andwould thus act as an etch stop for forming the fluid flow paths 154-158in the substrates 152 (e.g., where the fluid flow paths are formed usinga process such as deep reactive ion etching). After forming the fluidflow paths, 154-158, the negative photoresist material may be developedto provide the desired flow channel features. The photoresist materialmay then either be bonded directly or with an adhesive to body 172.

An alternative process may include waiting until the fluid flow pathsare formed in the substrates and the nozzle plates are attached to thesubstrates before laminating a photoresist material to the fluid supplyside 160 of the wafer 150. In this process, a curable or thermosetphotoresist material may be used to attach the ejection head structure44 to the body 172. In the case of a thermoset photoresist material, thephotoresist material may be cured when in contact with the body 172, ormay be cured before attaching the ejection head structure 44 to the body172. The cured photoresist material may also be attached to the body 172by use of an adhesive as described above.

As will be appreciated, the foregoing embodiments enable production ofmicro-fluid ejection device structures having a supply path densityranging from greater than 1.00 mm⁻¹ up to about 3.0 mm⁻¹. The increasedsupply path density enables the use of smaller substrates therebyreducing the cost of the micro-fluid ejection device structures.

It is contemplated, and will be apparent to those skilled in the artfrom the preceding description and the accompanying drawings, thatmodifications and changes may be made in the embodiments of theinvention. Accordingly, it is expressly intended that the foregoingdescription and the accompanying drawings are illustrative of preferredembodiments only, not limiting thereto, and that the true spirit andscope of the present invention be determined by reference to theappended claims.

1. A method of making a multi-fluid cartridge for holding multiplefluids in segregated containment localities, a cartridge body containingfluid supply paths in fluid flow communication with the containmentlocalities, the method comprising: printing an adhesive with a bond linedensity of at least about 1.2 mm⁻¹ on a fluid supply side of amicro-fluid ejection device structure; and adhesively bonding a circuitdevice, attached to the micro-fluid ejection device structure, to thecartridge body for flow of fluid from containment localities to a deviceside of the micro-fluid ejection device structure, wherein the act ofprinting comprises one of stencil printing and screen printing, andwherein the micro-fluid ejection device structure is one of a pluralityof micro-fluid ejection device structures diced from a wafer, each ofthe micro-fluid ejection device structures comprises an ejection headsubstrate and a nozzle plate, further comprising: applying a photoresistlayer to the wafer adjacent a fluid supply side of the ejection headsubstrates; and photodefining fluid flow channels in the photoresistlayer to provide fluid channels therein in fluid flow communication withfluid flow paths in the ejection head substrates.
 2. The method of claim1 wherein applying the photoresist layer to the wafer comprises one ofspin coating and spray coating a photoresist layer on the wafer.
 3. Themethod of claim 1 wherein applying the photoresist layer to the wafercomprises spray coating a photoresist layer on the wafer.
 4. The methodof claim 1 wherein applying the photoresist layer to the wafer comprisesweb laminating the photoresist layer to the wafer.
 5. The method ofclaim 1 wherein applying the photoresist layer to the wafer compriseslaminating two or more photoresist layers to the wafer, each of thelayers having photodefined fluid channels formed therein.
 6. The methodof claim 1, further comprising: attaching the nozzle plate to a deviceside of each of the ejection head substrates on the wafer, each of theejection head substrates having a fluid supply side and two or more ofthe fluid flow paths therein for supplying fluid from the supply side tothe device side of the election head substrates, wherein the fluid flowpaths in the ejection head substrates have a flow path density ofgreater than about 1.0 flow paths per millimeter.
 7. The method of claim6 further comprising photodefining the fluid flow channels in thephotoresist layer prior to attaching the nozzle plat to the substrates.8. The method of claim 6, further comprising attaching the circuitdevice to the device side of each of the ejection head substrates. 9.The method of claim 8, wherein the circuit device is attached to thedevice side of each of the substrates prior to stencil printing theadhesive.
 10. The method of claim 1, wherein the adhesive is stencilprinted after the wafer is diced.
 11. A method of making a multi-fluidcartridge for holding multiple fluids in segregated containmentlocalities, a cartridge body containing fluid supply paths in fluid flowcommunication with the containment localities, the method comprising:printing an adhesive with a bond line density of at least about 1.2 mm⁻¹on a fluid supply side of a micro-fluid ejection device structure; andadhesively bonding the micro-fluid ejection device structure to thecartridge body for flow of fluid from containment localities to a deviceside of the micro-fluid ejection device structure wherein the act ofprinting comprises one of stencil printing and screen printing, andwherein the micro-fluid ejection device structure is one of a pluralityof micro-fluid ejection device structures diced from a wafer, each ofthe micro-fluid ejection device structures comprises an ejection headsubstrate and a nozzle plate, further comprising: applying a photoresistlayer to the wafer adjacent a fluid supply side of the ejection headsubstrates; and photodefining fluid flow channels in the photoresistlayer to provide fluid channels therein in fluid flow communication withfluid flow paths in the ejection head substrates.
 12. A method of makinga multi-fluid cartridge for holding multiple fluids in segregatedcontainment localities a cartridge body containing fluid supply paths influid flow communication with the containment localities, the methodcomprising: printing an adhesive with a bond line density of at leastabout 1.2 mm⁻¹ on a cartridge body; and adhesively bonding a micro-fluidejection device structure to the cartridge body for flow of fluid fromcontainment localities to a device side of the micro-fluid ejectiondevice structure, wherein the act of printing comprises one of stencilprinting and screen printing, and wherein the micro-fluid ejectiondevice structure is one of a plurality of micro-fluid ejection devicestructures diced from a wafer, each of the micro-fluid ejection devicestructures comprises an ejection head substrate and a nozzle plate,further comprising: applying a photoresist layer to the wafer adjacent afluid supply side of the ejection head substrates; and photodefiningfluid flow channels in the photoresist layer to provide fluid channelstherein in fluid flow communication with fluid flow paths in theejection head substrates.
 13. A method of making a multi-fluid cartridgefor holding multiple fluids in segregated containment localities, acartridge body containing fluid supply paths in fluid flow communicationwith the containment localities, the method comprising: printing anadhesive with a bond line density of at least about 1.2 mm⁻¹ on acartridge body; and adhesively bonding a circuit device attached to amicro-fluid ejection device structure to the cartridge body for flow offluid from containment localities to a device side of the micro-fluidejection device structure, wherein the act of printing comprises one ofstencil printing and screen printing and wherein the micro-fluidejection device structure is one of a plurality of micro-fluid ejectiondevice structures diced from a wafer each of the micro-fluid ejectiondevice structures comprises an ejection head substrate and a nozzle platfurther comprising: applying a photoresist layer to the wafer adjacent afluid supply side of the ejection head substrates; and photodefiningfluid flow channels in the photoresist layer to provide fluid channelstherein in fluid flow communication with fluid flow paths in theejection head substrates.